1. Field of the Invention
The present invention relates to a resealable, easy open container wall, such as a can end. More particularly, the present invention relates to a resealable closure cap and a container cap assembly easily applied to a spout of a container wall which is capable of accommodating desired internal container pressures.
2. Description of the Prior Art
The prior art teaches various structures for containers such as drawn and ironed cans having end panels which have opening devices which are generally called "easy open ends" double seamed to the can. Examples of easy open ends of the prior art are described in U.S. Pat. Nos. 3,929,251; 3,977,341; 3,997,076; 4,024,981; and 4,148,410.
The market for containers having easy open ends may be extended, particularly, though not exclusively, with respect to containers having larger capacities. This may be accomplished through the utilization of a cap to close and reseal the spout or pouring opening defined by the easy open end. Without a resealable closure cap, the liquid contents of an open container could easily spill or be otherwise lost. Also, dissociable gases, i.e., carbonation, in the remaining liquid are readily lost from unsealed, open containers, thereby altering the character of the product.
One construction for a resealable closure cap assembly is taught in U.S. Pat. No. 4,580,692. See also U.S. Pat. Nos. 4,685,849 and 4,783,985. These patents teach constructions for such a resealable closure cap assembly in association with a selectively contoured can end to accommodate the resealable closure while retaining the advantages characteristic of the easy open end. These patents disclose a sealing cap having a seal portion, an arm for securement to the container wall by means such as a rivet and a tab for use in grasping the cap to move it from one position to another. The cap is generally circular and has the arm emerging therefrom at a position generally about 90.degree. degrees offset from the place where the tab projects outwardly.
U.S. patent application Ser. No. 338,096 U.S. Pat. No. 4,991,732 discloses venting of such a resealing cap during removal of the resealing cap from the container so as to resist undesired reverse displacement of the container wall end panel which would establish a potentially serious hazard. This application discloses the use of venting channels which are transversely located in an inwardly directed ledge of the closure. See generally U.S. Pat. No. 4,928,844.
U.S. Pat. No. 4,932,555 discloses such a system which creates zones of weakness between the cap and the rivet securing the arm connecting the cap with the rivet.
U.S. patent application Ser. No. 338,310 U.S. Pat. No. 4,982,862 is directed toward such a system wherein improvements are provided to the container wall spout.
U.S. patent application Ser. No. 338,580 U.S. Pat. No. 4,957,216 discloses a releasable fastening assembly in the form of an additional projection from the cap which is adapted to cooperate with a button-like member formed in a container wall to resist undesired rotation of the cap.
U.S. patent application No. 397,218 Abn. discloses the use of a plurality of stiffening ribs in such a reclosure cap so as to provide zones of different elasticity from other zones. It also discloses the absence of such ribs in the region connecting the arm which secures the cap to the container and the remainder of the cap. It also contemplates the possible omission of ribs from the region adjacent the arm in order to provide for venting in this region.
The disclosures of all of these U.S. patents and co-pending United States patent applications are expressly incorporated herein by reference.
The provision of commercially acceptable resealable easy open can end constructions for current and larger volume beverage containers requires ease of application of the resealing cap over the spout, sealed retention of remaining container contents and accommodation of inherent internal can pressure that builds after resealing the can. Also desired is a can end configuration having an easy open end which does not require the use of lever mechanisms or the like to accomplish opening of the pouring spout. Ideally, the easy open end is easily and readily opened by a user through the mere application of digital pressure in a simple and safe manner. Such construction of a resealable easy open can end should be accomplished without diminution of the convenience and cost effective nature of the basic easy open end construction during manufacturing, filling, handling, shipping, distributing, selling and consumer usage.
Experience to date with resealable caps and can end constructions, such as those disclosed in U.S. Pat. Nos. 4,580,692 and 4,648,528, the contents of which are incorporated herein by reference, has indicated a need to assure proper application and retention of the resealable cap over the spout defined by the easy open end.
Despite attempts and progress in this area of resealable container closures, there is still a need and a demand for further improvement. Accordingly, a new and improved resealable container closure is desired which is easily applied to the spout to provide an effective seal for an opened container.